A Brighter Moon

Many traditions persist that at some time in the past
the Moon was much brighter than it is now, and larger in appearance than
the Sun. In many rabbinical sources it is stated that the Sun and the
Moon were equally bright at first.(1)
The same statement was made to de Sahagun by the aborigines of the New
World: the Sun and the moon had equal light in the past. (2)
At the other end of the world the Japanese asserted the same: the Nihongi
Chronicle says that in the past the radiance of the moon was next
to that of the sun in splendor. (3)

Traditions of many peoples maintain that the Moon lost
a large part of its light and became much dimmer than it had been in earlier
ages.(4)

In order that the Sun and the Moon should give off comparable
light, the Moon must have had an atmosphere with a high albedo (refracting
power)(5) or it must have
been much closer to the earth. In the latter case the Moon would have
appeared larger than the Sun. In fact, the Babylonian astronomers computed
the visible diameter of the Sun as only two-thirds of the visible diameter
of the Moon, which makes a relation of four to nine for the illuminating
surfaces. This measure surprised modern scholars, who are aware of the
exactness of the measurements made by the Babylonian astronomers and who
reason that during the eclipses one can easily observe the approximate
equality of the visible disks.(6)

[B.
de Sahagun, Historia general de las cosas de la Nueva Espana
[Cf. the Peruvian tradition recorded by Pedro Sarmiento de Gamboa
in the sixteenth century, according to which Viracocha created the
Moon brighter than the Sun: Historia de los Incas, ch. 7.]